Interest in the omega-3 (as well as omega-6 and omega-9) fatty acids as health-promoting nutrients has expanded dramatically in recent years. A rapidly growing literature describes the benefits of polyunsaturated fatty acids in alleviating cardiovascular disease, atherosclerosis, autoimmune disorder, diabetes, and other diseases.
Extensive research indicates that omega-3 fatty acids reduce inflammation and help to prevent certain chronic diseases such as heart disease and arthritis. These essential fatty acids are highly concentrated in the brain and appear to be particularly important for cognitive and behavioral functions. In fact, infants who do not receive sufficient omega-3 fatty acids from their mothers during pregnancy risk improper vision and nerve development.
Omega-3 fatty acids are considered essential fatty acids, which are essential to human health but cannot be produced by the human body. For this reason, omega-3 fatty acids must be obtained from another source, primarily food.
Fish oils and plant oils are the primary dietary source of omega-3 fatty acids. Omega-3 fatty acids are found in cold-water fish such as salmon, mackerel, halibut, sardines, and herring. Omega-3 fatty acids are also found in flaxseeds, flaxseed oil, canola (rapeseed) oil, soybeans, soybean oil, pumpkin seeds, pumpkin seed oil, purslane, perilla seed oil, walnuts, and walnut oil. Also known as polyunsaturated fatty acids, omega-3 (and omega-6) fatty acids are beneficial to the human brain and the human body's normal growth and development.
Evolutionary assessments suggest that people in most western countries are consuming far less omega-3 fatty acids than now appears to be nutritionally desirable. Fish oils are the best sources of omega-3 fatty acids, but the consumption of fish is too low to meet the requirements. Efforts to supplement foods with omega-3 fatty acids have not been very successful because of the generally distasteful flavors and odors associated with the oils. The omega-3 rich fish oils are extremely susceptible to oxidation, thus requiring control of oxidation and off flavor development. Although antioxidants have been successfully added to fish oils to reduce the odor, a problem nevertheless remains particularly for individuals incapable of digesting omega-3 fatty acids in oil form as a result of ineffective enzyme production in the particular individual.
The extremely high sensitivity of omega-3 fatty acids to oxygen is related to: 1) molecular structure of the omega-3 acids; and, 2) liquid state of the fish oil containing omega-3 fatty acids. Some aspects of omega-3 oxidation are provided below for a better understanding of the disclosed method.
It is known to those skilled in the art that oxidation of organic compounds in the liquid phase (N. M. Emanuel, E. T. Denisov, Z. K. Maizus. Liquid Phase Oxidation of Hydrocarbons, Plenum Press, New York, 1967) consists of several consecutive steps. These steps are: (1) oxygen diffusion into the liquid phase; (2) initiation; (3) propagation; (4) branching; and, (5) termination.
Diffusion of oxygen (1) into the liquid is facilitated by the mixing of gas and liquid. The more intensively they are mixed, the faster oxygen saturation will be reached and the faster the oxidation reaction will occur. It is important to note that gas diffusion into solids is significantly slower than diffusion into liquids.
Chain initiation (2) during oxidation occurs as a result of the interaction between oxygen and the reaction center on the omega-3 molecule. The rate of initiation depends on the strength of C—H bond and on the stability of free radicals produced during the course of this type of reaction. Specific distribution of double bonds in omega-3 molecules makes these free radicals quite stable compared to other types of free radicals produced during the initiation reaction. Radicals produced as a result of the chain initiation reaction, reacts further with another oxygen molecule and is transformed into peroxy radical.
Chain propagation (3) is the reaction between a peroxy radical and another molecule of omega-3 fatty acid. A new free radical and hydroperoxide molecule are produced. It is important to mention that usually the chain propagation is a reaction between two separate molecules and its rate to a great extent depends on the velocity of molecular movement. The mobility of molecules in a liquid phase is high while mobility in a solid state is much slower. In a solid state, molecules do not move, but oscillate. This is why solid state chain propagation reaction rate is much slower.
Chain branching (4) occurs as a result of the split of hydroperoxides. In a liquid phase this reaction is the reason for the so-called self acceleration oxidation process. In a solid phase, this reaction is not significant because of the cell effect.
This leads to the conclusion that if omega-3 fatty acids can be converted and stored in a solid state with no any changes to its molecular structure, oxidative stability will increase.
Omega-3 fatty acids can also be made in capsule form with the primary constituent being either fish oil or flaxseed oil. It is known that all oils containing unsaturated fatty acids are very susceptible to oxidation by air oxygen and other oxidation agents. Oxidation of these oils causes dramatic and undesirable changes in their taste and aroma and tremendously decreases their nutritional value. This is the reason that these oils are recommended to be refrigerated.
Presently, the popular omega-3 fatty acids consumed by humans are provided in the form of oils. Following consumption, omega-3 oils (chemically -triglycerides of the omega-3 fatty acids) are hydrolyzed into free omega-3 fatty acids and glycerin by the actions of stomach and pancreatic juices. However, many people have difficulty digesting oils and fats, thus placing additional stress on the pancreas, liver and gallbladder.
The pancreas secretes pancreatic juice, which contains three enzymes that break down carbohydrates, fats, and proteins. The gallbladder secretes bile that helps dissolve fats. Digestive disorders are possible in some individuals because either the pancreas or gallbladder are unable to function properly. This ultimately may preclude a particular human body from consuming sufficient amounts of oils containing omega-3 fatty acids.
The prior art also discusses various methods for manufacturing salts (mainly, calcium salts) of unsaturated fatty acids. These methods are based on the reaction of fats with calcium oxide in the presence of water at high temperature. U.S. Pat. No. 858,295 issued to Krebittz describes the preparation of soap and having the first production step preparation of calcium salt of fatty acid. U.S. Pat. No. 898,547 issued to Barrett, describes the manufacture of insoluble lime salts of fatty acids by reacting fatty matter with hydrate lime at 200° C. U.S. Pat. Nos. 6,229,031, 6,559,324, 6,576,667 issued to Strohmaier and U.S. Pat. No. 5,382,678 issued to Vinci describe the preparation of calcium salts from unsaturated fatty acids, including omega-3 acids.
All of the aforementioned patents described above teach a synthetic method based on reaction of the liquid oil with a stoichiometric excess of calcium oxide in the presence of water. As a result, these patented procedures produce a product containing calcium salts of fatty acids. These references disclose that the calcium salt product contains up to 5% unreacted oil and further contains glycerin that remains in the product. It is to be noted that calcium salt of omega-3 fatty acids made according to Strohmaier and Vinci have a very high pH due to the remaining unreacted calcium oxide present and as a consequence, cannot be used for human consumption. It is also important to note the patents described above do not provide, teach or suggest the possibility for the preparation of other than calcium salts of fatty acids.
Finally, all salts of omega-3 of fatty acids produced in accordance with the patents discussed above contain unhydrolized triglycerides, non-reacted calcium oxide or calcium hydroxide which provide little or no nutritional value to the salts produced.